Association between the HFE mutations and longevity: a study in Sardinian population.
Hereditary hemochromatosis is an HLA-linked inherited disease characterised by inappropriately high absorption of iron by the gastrointestinal mucosa. The cysteine-to-tyrosine substitution at codon 282 of the HFE encoding gene sequence is responsible for the disease, although other variants, as H63D and S65C, may modify the affinity of the protein for transferrin receptors. We have recently reported that C282Y mutation is significantly increased in very old (>90 years) Sicilian women, suggesting a role in attainment of longevity. In addition, an increase of H63D polymorphism was also observed in these women but the difference was not significant. To validate and extend these results we investigated the distribution of these three common HFE gene mutations in Sardinian centenarians and controls. DNA samples, obtained from 61 controls and 57 Centenarians, were typed for HFE polymorphisms using sequence specific primers. Among the controls, none was heterozygous for the C282Y mutation, 15 were heterozygous for H63D mutation and one for S65C. Among the centenarians, none was heterozygous for the C282Y mutation whereas 25 were heterozygous for H63D mutation and four for the S65C mutation. No significant differences were observed in frequencies of the different alleles between young and centenarians both on the whole and when the data were analysed according to gender. However, there was a trend for an increased frequency of H63D allele in centenarian women (24 vs. 17%, i.e. 19/80 vs. 13/78). It is noteworthy that the cumulative frequency of H63D mutations in Centenarian and very old women from Sardinia and Sicily is 22 vs. 11%, i.e. 30/136 vs. 23/210, P=0.008. These findings are consistent with the hypothesis that there may be a survival difference for centenarian women, among carriers and non-carriers of alleles involved in iron sparing.